It sounds like you don't have your fabric straight on the take up roller. It takes practice to load a quilt correctly. Check your leaders and make sure they are straight and haven't stretched out of line. They should be the same length on each end and the center. Carefully load your backing, batting and top. Perhaps you might want to try the method I recently learned - I float the top - which means it's not attached to a roller at all. I stitch across the top of it once it's in place and then proceed from there. I secure the top with clips designed for this purpose. I bought them at
www.ericas.com and they are called quilter's C clamps and come in a couple sizes. Hope this helps. Also, you might want to check out youtube for videos on how to load a quilt. That is what I did with my first quilt. I didn't know which was was up back then!!!